1. Technical Field
This invention generally relates to baseball and softball bats and, more particularly, to reconfigurable bats that allow for the replacement of the barrel should a different level of performance be desired or should the barrel become damaged.
2. Background Art
The disclosures and inventions of the past are deficient in teaching the use of a bat with a barrel section that may be removed from the bat and replaced with a different barrel section when a change in the performance characteristics of the bat is required or when the barrel section becomes damaged. Rather, the approaches of the past address the issues of performance and durability by trading-off one against the other in an attempt to achieve a balance which the user might appreciate.
The designers of baseball and softball bats have had as a primary object, a bat that can hit a ball long distances. Designers have as a secondary object, a bat which is durable and can survive repeated impacts with the ball. It is difficult to accomplish one of these objectives without compromising the other.
The characteristics of a bat are very largely determined by the types of materials and the geometry of the components including a thickness of the barrel section of the bat. Depending upon the performance and/or durability desired, the bat may be very durable or easily susceptible to damage during play. Likewise, a bat's performance, measured by the batted ball speed, may be high or low. Most high performance bats manufactured today are hollow. They rely upon the deformation of the barrel wall, principally in the hoop mode, to provide a so-called “trampoline effect” which leads to higher batted ball speeds. Bats of this construction can be as much as 50% more efficient than solid wood bats. That is, the batted ball speed can be as much as 50% higher for hollow bats than for wooden bats. Because such high performance gives an advantage to the batter, most players prefer to use a bat with as high a performance rating as possible. Higher batted ball speeds, however, put the pitcher and other infielders at some risk of being struck by a ball traveling so rapidly that they have insufficient time to react. To protect players in the infield, bat performance is generally regulated. To be competitive, bats must perform at or near these regulated limits. However, even to achieve these regulated limits, barrel walls must generally be thinned to the point that durability becomes an important issue. It is common, among the highest performing population of bats, especially in the hands of good athletes, for these bats to be damaged within 50–500 impacts. This damage renders the bats of the past unsuitable for further use.
The first bats ever produced were made from solid wood and were of one piece construction. This design endured without significant change for about ¾ of a century until hollow aluminum bats were introduced. These aluminum bats and subsequent composite bats have followed the original wooden bats in form except for their hollow construction. Designers have continued to struggle with the tradeoff between performance and durability. Their solutions have been deficient in many regards.
Numerous solutions have been proposed for improving durability, all with varying degrees of success. In each case, efforts to improve the durability of the bat generally result in a reduction in performance. The liveliness of the bat, principally resulting from the so-called “trampoline effect” is closely tied to the stiffness of the barrel section of the bat. To some degree, reducing stiffness increases the trampoline effect and vice-versa. Increasing thickness of the barrel wall quickly increases the bending stiffness of the wall, allowing the wall to deform less, and reducing the trampoline effect as a result. Another shortcoming resulting from these durability increasing approaches is an increase in the bat's weight and its polar moment of inertia, both making the bat more difficult to swing rapidly and decreasing the batter's ability to hit the ball well.